They never banned them, they just put a pay wall in to stop people getting it free from the Netherlands. They've never banned paying customers.
I know for a fact they blocked hola IPs last year, while using other proxies allowed you to watch. There was no paywall, because you didn't even have to login.
I understand that there is a paywall now... but whether you're paying or not, you're fraudulently representing that you're outside of the US. If the NFL wanted to offer this to US customers, they'd already be doing it.
There is nothing stopping them from taking your money and then blocking whatever proxy you're using down the road. That saves them a little bandwidth, actually.